Shaft sealing device



A'Pl'l 2, 1940 E. H. sTEED'MAN 2,195,877

SHAFT SEALING DEVICE Filedpril a, 193e V: e shuts-sheet 1 b m m \m l fz'12 l' I /a 1H IUI `lll 1 Il 9 7 7 In y 33 I y l l! :T m 'A 'DW//v H 5resp/14N i? www M ATTORNEY.

lApril 2, 1940.

E. H. sTEEDMAN 2,195,877

v SHAFT SEALING DEVICE Filed April 8, 1936 2 Sheets-Sheet 2 @zw lvINVENTOR. 'Dw//v H. .STEFDMn/v BY UMZMM ATTORNEY.

v operating.

Patented Api. 2, '1940' l-iJNiTlsnl STATE A 2,195,311 snm sEaLmG DEVICEEdwin n. s foodman, st. Louis, Mo., assignmto PATENT OFFICE omis'Manufacturing company. wouston, Mo.,

corporation of Missouri Application April s, 1936, serial No. '13,zs1

Y s claims. (ci. zas- 11) that will remain gas tight for a long period.of

time, especialy when the associated machine is subjected to intermittentoperation. Where the .coacting sealing surfaces are at all times'covered with oil or. otherA sealing fluid, undue wear of the surfaces isprevented and any leakage pastv the joint must be of oil or sealing uidrather than gas, and since a sealing joint can be made fluid tight withlittle diillculty. any leakage between the surfaces will be prevented.

4To insure satisfactory operation of sealing surfaces in a device wherethe normal oil level is belowthe level of the sealing surfaces, it isnecessary to provide a sumcient amount of sealingfiuid or oil to coverthe sealing surface at all times, including periods when the device isnot Thus one of the objects of the present invention is to provide ashaft sealing devicein an appliance having the internal oil supply levelbelow that of the shaft with means for submerE- f ing the sealing devicewith oil at all times.

This is accomplished in the present invention by providing an auxiliaryy sealing' device which with the main sealing device Iwill form a pocket-forzoil or sealing fluid which may lbe supplied from a reservoir;

' Another object of this invention is to .provide main and auxiliaryshaft sealing devices which are actuated'independentiy of each other sothat wear of one-will not aii'ect the operation of the other and so thatthe design of the sealing niem-v bers is not limited by. the requirementof equal wearing properties.

Another object of'niis invention is to' provide' the necessaryoilpockets around the main 'shaft isol sealing surfaces so th'at anyleakages vtherethrough will be of oil rather than air or gas.

Another object'of this invention is'to provide a sealing device whoserubbing or bearing' surfaces ,will maintain close and tight contact evenafter considerable wear.

AOther objects and vadvantages as well as the method of accomplishingthe above set forth objects wil appear from the following detaileddescription.

'Ihe accompanying drawings illustrate several forms of the invention anda description of the ,5 same will follow, it being understood that thevinvention is also capable of embodiment in 'nu' merous modied andamplified forms falling within the scope of the appended claims.

In the drawings: y 10 Figure 1 is a view partially in vertical sectionand partially in front elevation, of a compressor embodying my improvedshaft sealing device. Fig. 2 is a-fragmentary sectional view of amodified form o f my shaft sealing device. 15 Fig. 3 is afragmentaryview, in section, of a modified form of my shaft sealingdevices v Fig. 4 is a fragmentary view, in section, of anothermodiiication'embodying my invention,and

Figs. 5'and 6 are fragmentary views, in sec- 20 --tion, of still furthermodifications of shaft seal? ing devices embodying my invention.-

Referringiirst to Fig. 1 of the drawings, I have there illustrated acompressor designated generally by the numeral Il and comprising acrank- 25 case I3`having an opening I5 in one of its walls andi a secondopening I1 in its opposite wall. 'I'he numerals I 9 and 2| designateconnecting rods of ythe usual form. Y v

Opening I5 in one wall of the casing has lo- 30 cated therein a bearingsupport member 23 which may be of substantially annular shape andfastened against the casing over the opening I 5 by a plurality of shortcap screws 25. 'Ihe bearing support 23is so designed as to receive andhold a roller bearing 21. While I have illustrated a specic form ofroller bearing, the design and construction thereof form no part of mypresent invention. A crank shaft 29 Iis located within the'crankcase andhas one end thereof supported.v 40 l by the above described rollerbearing, the inner race of the roller' bearing being adapted to beforced on the crank shaft so as to form a gas tight joint. The other endof the crankshaft may be supportedby a second roller bearing 3| 45 whichis located-in thev opening I1 in the other wall' of the casing and whichis held inproper operative position by any suitable means.

Means for drivingthe crank shaft may comprise a pulley 33 mounted on atapering portion of the crank shaftand held against rotation by a keyand a locking nut 31. I I An oil' retaining'pocketf is provided for thepurpose of supplying oilffrom the `crank case oil described. Anydesirable means may be e'mployed for elevating a sufficient quantity ofoil from the crank case oil supply to the oil retaining pocket. Fig. 1shows an oil ring 43 which rotates with the crank shaft and delivers oilto the adjoining control surfaces 45 of the crank shaft. Centrifugalforce causes this oil to travel outwardly on the control surface andthen to be trapped inside of the annular washer 41. The oil then travelsthrough the passage 49, the excess .of oil not used for lubricating theconnecting rod is thrown out of the open end of the passage through ahole 5I and onto a projection 53 of the crank case from where it dripsinto the oil retaining pocket 39. This method of delivering oil to thepocket is not claimed as a part of this invention, it being understoodthat any method of delivering oil from the crank case to the oil pocketmay be used without departing from this invention. Another satisfactorymethod of supplying oil to the pocket would be to provide the -crankshaft with a blade like projection 54 which would throw oil from thecrank case onto the projection 53.

'I'he main shaft sealing device is provided for the pulley end of thecrank shaft and will now be described. The numeral 55 designates aflexible metal bellows having its outer end secured in an oil and gastight manner as by brazing to an annular plate 51. A gasket 58 forms agas and oil tight joint between the plate 51 and the member 23 whenannular member 59 is drawn against it by cap screws 6|. The inner end ofthe flexible metal bellows is similarly secured to annular member 63which may be composed of any suitable metal. A-plurality of helicalcompression springs may extend between the metal plate 51 and the member83, small projections 61 and the recesses 69. being provided to maintainthe helical springs in proper operative positions. Any other suitableform of spring means may be used if desired. One endAof an annularsealing member 1I, which maybe of the shape shown in Fig. .1 and of anysuitable material, cooperates with the annular member 63 to form a gastight joint. The member 1I may be formed integral with the member 53 ifdesired. The' other end of the sealing member 1| is pressed against theinner race of the roller bearing 21 by the action of the springs 65 toform the main sealing surface.

An auxiliary pair of sealing surfaces is formed by an annular member 13,whose shape in cross section may be substantially that shown in Fig. 1and whose diameter may be slightly greater than that of member 1|, andthe surface of the inner race of the roller bearing. The member 13 issecured in a gas tight manner, as by brazing, to the inner edge of aresilient corrugated annulus 15 whose outer edge is similarly secured toa ring member 11. A means for maintaining close operative rubbingengagement between the an- 'nular member 13 and the inner race of theroller bearing may comprise a spring. plate 19 whose outer diameter issubstantially the same as the outer diameter of ring 11.- The assemblycomprising members 13, 15, 11 and 19 may be held in their properoperative positions by being clamped between an overhanging shoulder 8|of member 23 and the outer race of the roller be'aring. I have merelyillustrated one form or means for holding the auxiliary sealing deviceand do not wish to be restricted thereto since other structureseffective for the same purpose may be employed Without departing fromthe scope of the invention.

It can be seen from the drawings that an oil reservoir or pocket will beformed by the members 51, 55, 63, 1I, 13, 15, 11, 8| and the inner raceof the roller bearing, into which oil from the oil retain pocket 39 canflow and be retained. The space provided for the storage of the oil isrelatively large due to the construction employed insuring a surplus ofoil around the sealing surfaces even though some may leak back into thecrank case or be forced out due to gas or air pressure. An oil duct 83may be drilled angularly from the surface 85 and allows oil in theretaining pocket 39 above the level of surface 85 to fiow down andaround the auxiliary sealing member 13 and to run out through the rollerbearing and into the crank case.

As described the sealing members 1I and 13 are pressed against acooperating contact surface as the inner race of a'roller bearing byindependent or individual holding means, causing the operation of eachpair of sealing surfaces to be independent of the other pair. This isespecially advantageous if one of the sealing members wears more Athanthe other for both of the sealing devices will continue to operatesatisfactorily which they would not do if they were formed integral witheach other.

While Fig. 1 illustrates a form of my invention as applied to a. deviceusing roller bearings as a crank shaft supporting means, the otherfigures show a form of the invention as applied to a plane bearing. Thenumerals employed in the description of Fig. 1 designate similar partsinthe other figures. Fig. 2 shows a form of the invention utilizing anend of an enlarged portion of the crank shaft as a cooperating contactsurface for the sealing members. 'I'he numeral 81 denotes a bearingsurface which cooperates with the bearing surface of the enlargedportion 89 of the crank shaft to form a suitable crank shaft support.The enlarged portion 89 of the crank shaft may be an annular memberdriven onto the crank shaft or an enlarged portion formed integral withvthe crank shaft. In Fig. 2 the sealing members 1l and 13 may cooperatewith the contact surface on the end of the enlarged portion of the crankshaft to form main and auxiliary sealing surfaces which form a pockettherebetween to retain a supply of oil.

Another form of the invention is shown in Fig. 3 where a different typeof auxiliary sealing member is shown. The auxiliary sealing member 9imay be of any resilient packing material such as felt or treated ropeand is heldin a recess 93 of the crank case by an annular plate 95 and aspring ring 91. In Fig. 3 this auxiliary sealing member cooperates withthe bearing surface of the enlarged portion of the crank shaft to forman auxiliary sealing surface. The main sealing surface is formed as inFig. 2 and, withthe auxiliary sealing surface, forms a pocket to retaina supply of oil. A single spring 99 which may be used in any of theother forms of the invention instead of the plurality of springspreviously shown, is shown in this drawing with the form of the annularmember 63 changed to accommodate the single spring.

In the form of the invention shown in Fig. 4, the contact surfaceincludes the inner face of the annular member |0I which may be securedto the crank shaft in any suitable manner. The metallic bellows andspring are similar to those used in the oil pocket is subject to theinternal crank case Fig. 3 and are supported'by a ring |03 clamped intoposition by an'annular clamping member |05. The auxiliary sealing memberlis similar to the one shown in Fig. 3, but 'here makes rubbing contactwith the bearing surface ofthe crank shaft, yas no .enlarged portion ofthe crank shaft need be used in this'form of the invention. Theauxiliary'sealing member as' before forms a pocket with the main sealingmember and the contact'surface to retain a supply of oil or sealingfluid.

Fig. 5 shows a form of the invention wherein. an-annular resilientgasketl |01 maybe used as a main' sealing member. It may be composed ofany suitable material such'as leaded or treated rope and is pressed'intorubbing contact with the surface of -the crank shaft by a clamping ringIUS which may screw into a recess inthec'rank case which also serves toh old the main sealing member. v-The auxiliary sealing memberlshownvhere may be similar to the type shown in' Fig.1 4. f i

The above described forms of the invention provide satisfactory shaftsealing vdevices adaptable to a` compressor having a crank case pressurewhich greatly exceeds the lexternal or atmos- 'pheric pressure or one inwhich the crank case pressure is lower'than atmospheric. With theinternal pressure'greatlyln excess of .the external pressure,l anyopening between the main seal ing surfaces will be instantly'lied withoil since pressure. vAs it is easy to seal the surfaces from an oilleakage, the oil Iwill not pass through the agiopening to .the outsidein any, large amounts and thus any leakage of gas is prevented. Withaninternal pressure slightly-lower than the ex-v ternal pressure, thecapillary attraction between di)V pressure is appreciably less than theexternal or the .main sealing surfaces will be adequate to maintain 'alm of oil therebetween to prevent leakage into the crank case. When theinternal form of the invention as shown in Fig. 6 may be used. In Fig. 6the main, and auxiliary sealing surfaces are similar to those shown'inFig. 1. In addition an external auxiliary sealing member 4l i3 isprovided. This sealing member may be of any suitable material suchasleather or felt and may be held inv position by a clamping orl holdingring H51 The clamping ring may be screwed into a recess' ||1 in anannular casing iis which may be formed integral with the ring 59 or vformed separately and secured thereto in any suitable manner. Itisobvious that in place of the type of packing shown, any other sealing g'means for holding oil in pocket |2| may be employed to eiect the samepurpose. An external oil pocket 2| is thus formedy between the main fsealing member and the external auxiliary sealing member. lAn oil cap|23 provided with a hole, |25therein is provided for an opening |21 inthe annular casing. The external oil pocket may be lled with oilorsealing uid through this opening. An external .oil pocket of suitableforfnmay be used with any of the forms ofthe invention 'previouslydescribed. Y

It can be seen that the external oil Apocket issubject pressureconditions 'external the crank case due to the hole in the o'il capwhile,

the internal oil pocket is subject to pressure conditionsinside ofthecrank case'. If theA ex ternal' crank ca se pressure greatlyexceedsjthe internal pressure, anyspace between theVA mainsealing'surface will beimmediately filled with oil Afrom the externalpocketfdu'eto the pressure difference and thus since' lan oil seal isreadily formed by the sealing surfaces, any leakage therethrough will bevery slight or totally prevented. internal oil pocket functions asdescribed .before should the internal crank case pressure exceed theexternal crank -cas'e pressure(v It will be noted that in'allformsof theinven` tion show n, the so-'called main and auxiliaryv ,sealing membersare' pressed against the surface with which theyV coact by independentmeans Thus even though one of the 'sealing members should wear more thanthe others, all members Willnevertheless maintain tight rubbing -contactwith the coacting surfaces. There will likewise bend tendency -for onemember to warp due to wear of the other' .member which would occur -Ywere they formed on the same member with the oil pocketbetween. Theindependent actuation of the sealing members-also makes it possible to.use Ydiiierent materialsin the construction:

ofeachif so desired.

While the above description and drawings illustrate several formsA o fthe invention, it is to be understood that it is capable of embodimentinnumerous othery forms within the' scope of the appended claims.'

-1. A sealing device to prevent leakage between a shaft and an enclosedcasing comprising two sealing members, a contact surface adaptedftov'cooperate in rubbing 'engagementjwith the sealing members, vindividualresilient holding means" for each sealing member to maintainit inrubbing engagement with the contact surface, a

p ocket adapted to retain a fluid between the sealv ing members, -apassage between the pocket and the casingand means to keep said pocketsupplied with uid from said casing.

2. ANshaft-sealing device to 'prevent 'leakage between anopeningin anl.enclosed casing and a shaft, comprising two sealing members, aconlvtact surfacefor cooperation with the` ,sealing members, individualresilient holding meansfor each sealing member to maintain it in rubbingengagement with-thecontact surface, said resilient Vholding means:Aallowing independent movement of each sealing member, a pocketincluding.

the space between saidsealing members, a passage between the pocket andthe enclosed casing vand means to. supply said' pocketA with sealingfluid.

.3. A shaft-sealing device vto prevent'leakage between a shaftandanenclosed casing comprising two annular sealing members surrounding theshaft, a contact surface rotatable with the shaft and positioned tocooperate withfboth of the sealing members, a plurality of springspositioned around each sealing member to maintain itinrubbing engagementwith the contact surface,I a pocket communicating with .the space Ibetween the two sealing members and adapted to retain a supply of uid, apassage between 'the pocket and the enclosedl casing and means tosupplyl the pocket with fluid from the enclosed casing.

4. In a compressor or the '.flike, av rotatable shaft,v a. casingprovided with an lopening-through which the shaft extends, an oilreservoir in the casing below the shaft, a bearing for the shaftincluding a fixed part carried by the casing at the opening and arotating part carried by the shaft, two annular sealing memberspositioned around the shaft, a contact surface on the rotating bearingpart, individual resilient means for each sealing member to maintain itin engagement'with the contact surface to form a seal, an oil pocketadjacent the opening around the shaft and including the space betweenthe sealing members, a passage between the oil pocket and the casing andmeans to supply oil to the pocket from the oil reservoir to completelycover the seals at all times.

5. In a compressor or the like, a rotatable shaft, a casing providedwith an opening through which the shaft extends, an oil reservoir in thecasing below the shaft, two annular sealing members around the shaft, acontact surface for cooperation with the sealing members, individualresilient holding means for maintaining each sealing member inengagement with the contact surface to form a seal, a flexible memberextending between each sealing member and the casing, an oil pocketadjacent the opening around the shaft including the space between thesealing members vand the exible members, a passage between the oilpocket and the casing and means to supply oil to the pocket to cover theseals.

6. In a compressor'or similar machine, the combination of a crankshaft,a crankcase having an opening in one of its walls through which saidcrankshaft passes, a contact surface rotatable with said crankshaft, twoconcentric sealing members encircling the shaft and engaging the contactsurface, an individual springing means for each sealing member tomaintain it in engagement with the contact surface, a bellowssurrounding the shaft and attached to one end by a gas tight connectionto the inner sealing member and at the other end by a gas tightconnection to the crankcase, a'gas tight connection between the othersealing member and the crankcase, an`oil pocket formed by the contactsurface, the two sealing members, the bellows, and the gas tightconnection, a passage between said oil pocket and the crankcase andmeans to keep said oil pocket supplied with oil from the crankcase.

7. In a compressor or similar machine, the combination of a crankshaft,a crankcase having an opening in one of its walls through which saidcrankshaft passes, a contact surface rotatable with the crankshaft, twoconcentric sealing members encircling the shaft and engaging the contactsurface, a plurality of springs arranged around the inner sealing memberfor maintaining it in engagement with the contact surface, spring meansfor maintaining the outer sealing member in engagement with the contactsurface, a flexible gas tight connection between each of the sealingmembers and the crankcase, an oil pocket formed by the contact surfaceand the two sealing members and their respective gas tight connections,a passage between the crankcase and the oil pocket and means, to keepthe oil pocket supplied with oil from the crankcase.

8. In a compressor or similar machine, the combination of a crankshaft,a crankcase having an opening in one of its walls through which saidcrankshaft passes, a rotating part carried by the shaft, two concentricsealing members encircling the shaft and engaging a contact surface onthe rotating part, individual spring means for each sealing member tomaintain it in engagement .with the Contact surface, a bellowssurrounding the shaft and attached at one end by a gas tight connectionto the inner sealing member and at the other end by a gas tightconnection to the crankcase, a flexible diaphragm attached between theouter sealing member andthe crankcase for a gas tight seal and an oilpocket formed by the contact surface, the two sealing members, thebellows, the flexible diaphragm, and the crankcase, a passage betweensaid pocket and the crankcase, and means to keep said oil pocketsupplied with oil from the crankcase.

EDWIN H. S'I'EEDMAN.

